55717

WDR11

BRWD2|DR11|WDR15;WD repeat domain 11;WDR11;WD repeat domain 11

WD repeat domain 15|WD repeat-containing protein 11|WD repeat-containing protein 15|bromodomain and WD repeat-containing protein 2

10q26

protein-coding

Count: 2; Pubmed_search,Generif

oncogenes and tumor suppressor genes are clustered around recombination hot spots or fragile sites in the genome, because double-strand break is the common initial step in translocation, deletion and gene amplification. FGFR2 gene on human chromosome 10q26 is amplified in diffuse-type gastric cancer, while WDR11 gene on human chromosome 10q26 is disrupted in glial tumors. Here, we investigated genomic structure around FGFR2 and WDR11 loci. The FGFR2 gene, consisting of 21 exons, was located within nucleotide position 485637-605687 of NT_030764.5 (reverse orientation), and WDR11 gene was located within nucleotide position 6515786-6574126 of NT_008902.12 (forward orientation). Because nucleotide position 1-91397 of NT_030764.5 corresponded to nucleotide position 6639437-6748623 of NT_008902.12, FGFR2 and WDR11 genes were found to be closely linked in tail-to-tail manner with an interval of ca. 570 kb. Due to the deletion of exon 21 within FGFR2 amplicons, exon 21 is substituted by exon 20 or other aberrant exons in aberrant FGFR2 transcripts previously isolated from KATO-III, OCUM-2M and HSC43 cells. Mapping of aberrant exons and deletion junctions around the WDR11-FGFR2 locus in KATO-III and OCUM-2M cells revealed that inverted-type recombination occurred through end joining of the FGFR2 locus on one allele and that on the other allele. Amplification of FGFR2 gene with such recombination around exon 21 results in exclusion of WDR11 gene from the FGFR2 amplicon. tumor suppressor genes closely linked to oncogenes might be excluded from amplicon through a breakage-fusion-bridge process during oncogene amplification.

Allelic deletions of 10q25-26 and 19q13.3-13.4 are the most common genetic alterations in glial tumors. We have identified a balanced t(10;19) reciprocal translocation in the A172 glioblastoma cell line which involves both critical regions on chromosomes 10 and 19. In addition, loss of an entire copy of chromosome 10 has occurred in this cell line suggesting that the translocation event may provide a highly specific critical inactivating event in a gene responsible for tumorigenesis. Positional cloning of this translocation breakpoint resulted in the identification of a novel chromosome 10 gene, WDR11, which is a member of the WD-repeat gene family. The WDR11 gene is ubiquitously expressed, including normal brain and glial tumors. WDR11 is composed of 29 exons distributed over 58 kilobases and oriented towards the telomere. The translocation resulted in deletion of exon 5 and consequently fusion of intron 4 of WDR11 to the 3' untranslated region of a novel member, ZNF320, of the Kruppel-like zinc finger gene family. Since ZNF320 is oriented toward the centromere of chromosome 19, both genes appeared on the same derivative chromosome der(10). The chimeric transcript encodes the WDR11 polypeptide, which is truncated after the second of six WD-repeats. ZNF320 is also expressed in A172 cells, although it is not clear if the translocation affects the expression of the altered gene because of the presence of another unrearranged gene on chromosome 19. We suggest that, because of its localization in a region frequently showing LOH and the observation of inactivation of this gene in glioblastoma cells, WDR11 is a candidate gene for the frequently proposed tumor suppressor gene in 10q25-26 which is involved in tumorigenesis of glial and other tumors showing frequent alterations in the distal 10q region.